Ding Xiaokun, Wu Guannan, Zhang Di, Yang Long, Wang Aobo, Li Sheng, Gao Li, Cui Zhengguo, Jiang Tao
School of Ocean, Yantai University, Yantai, China.
School of Hydraulic Engineering, Ludong University, Yantai, China.
Front Microbiol. 2025 Aug 5;16:1650890. doi: 10.3389/fmicb.2025.1650890. eCollection 2025.
is a key picocyanobacterium in coastal ecosystems, yet its seasonal bloom dynamics and environmental responses remain unclear in temperate coastal seas. Here, we integrated flow cytometry and gene analysis to investigate its bloom development and community succession in Laizhou Bay, based on 3 years of 10 seasonal surveys and a year-long monthly observation at a fixed station. blooms reached their peak in summer (up to 10 cells mL), particularly in the southern part of the bay, with high abundances in autumn as well. Phycoerythrin-rich consistently dominated the community (>70%), especially during autumn blooms. Genetic analyses revealed that summer-autumn blooms harbored high clade diversity (S5.1 II, III, V, and VII), whereas winter and spring communities were simpler, dominated by S5.1 I and IV. Notably, S5.2. VIII gradually increased in relative abundance during bloom development, exceeding 50% in late autumn. Temperature emerged as the primary regulator of dynamics, with cell abundance increasing exponentially with rising temperature. Bloom events were consistently triggered above 26°C. In addition, external nutrient inputs, particularly riverine pulses accumulating from summer to autumn, contributed to bloom persistence and genetic diversification. This study provides valuable insights into the mechanisms regulating blooms and offers a methodological framework for understanding and predicting microbial community responses to the combined effects of climate change and anthropogenic disturbances in coastal ecosystems.
是沿海生态系统中的一种关键蓝细菌，但在温带沿海水域，其季节性水华动态和环境响应仍不清楚。在此，我们结合流式细胞术和基因分析，基于莱州湾3年的10次季节性调查以及在一个固定站点进行的为期一年的月度观测，来研究其水华发展和群落演替。水华在夏季达到峰值（高达10⁶个细胞/毫升），特别是在海湾南部，秋季的丰度也很高。富含藻红蛋白的群体一直占据主导地位（>70%），尤其是在秋季水华期间。遗传分析表明，夏秋季节的水华具有较高的进化枝多样性（S5.1的II、III、V和VII），而冬春季节的群落则较为简单，以S5.1的I和IV为主。值得注意的是，S5.2.VIII在水华发展过程中相对丰度逐渐增加，在深秋超过50%。温度成为其动态变化的主要调节因素，细胞丰度随温度升高呈指数增长。水华事件在26°C以上持续触发。此外，外部营养输入，特别是从夏季到秋季积累的河流脉冲，有助于水华的持续和遗传多样化。本研究为调节水华的机制提供了有价值的见解，并为理解和预测沿海生态系统中微生物群落对气候变化和人为干扰综合影响的响应提供了一个方法框架。
